This invention relates to vineyard trellis systems, and, more particularly, to a vine support system employing trellis wires supported on cross arms.
Growing and harvesting grapes and other similar vine crops tends to involve a great amount of care and labor. In addition to the usual necessities such as water and fertilizer, the vines must be trained on a trellis to support the grapes for proper growth, ripening, and harvesting. In addition, the vines must be pruned regularly and trained to intertwine with the trellis. Establishing a trellis system is a primary requirement for a vineyard, and the time and materials involved in setting up a trellis for each vine involves a large expenditure. Any measure that can reduce the cost of materials and labor in this regard comprises a useful advance over the prior art.
A typical vineyard arranged to be mechanically harvested will be planted so that there will be a plurality of parallel rows with spaced apart grape plants in each row. A trellis system is provided by installing a plurality of vertical posts spaced along each row, usually a post at each plant with an end post at each end of the row. One or more trellis wires are extended along each row, the wires supported by the vertical posts and anchored under tension to the end posts. The vines are grown along the trellis wires, the vines growing in a manner and at a height so that the grapes can be readily harvested therefrom.
One prior art method of attaching the trellis wires to the intermediate wooden posts has been by the use of simple staples. In vineyards that are not mechanically harvested, this is a rapid, inexpensive and effective way to form a trellis system. However, staples have been shown not to withstand the rigors of mechanical harvesting, particularly when the mechanical technique involves shaking the trellis to cause the grapes to fall. Shaking may pull the staples from the posts. Also, wooden stakes may not endure many years of exposure to the elements, and must be replaced periodically.
In recent years more sophisticated trellis systems have been introduced, using metal or plastic posts to carry the trellis wires. The posts may support various types of arms that are screwed or bolted to the posts to engage the trellis wires, or the trellis wires may be secured to the posts by twisted wire arrangements. Although these systems generally have proven to be more sturdy and durable than the older wooden grape stakes, their use typically involves more labor to install the support arms or twisted wire ties. There is an unmet need in the prior art for a vineyard trellis system that is simple and inexpensive to install while being strong enough to withstand mechanical harvesting and long-term exposure to the elements.
The present invention generally comprises a trellis system for supporting grape vines and similar crop or flower plants. A salient feature of the invention is that it is easily installed and maintained, and involves a minimum of expense for materials and labor.
In one aspect, the trellis system includes a vertical post having one or more slotted apertures extending horizontally therethrough. A plurality of cross arms are provided, each cross arm fashioned and dimensioned to snap-engage in one of the slotted apertures and to extend horizontally outwardly from the post. The cross arms are adapted to support lateral trellis wires which engage the canes of a vine crop.
In a further aspect of the invention, a trellis cross arm is fashioned from a generally planar sheet of metal or plastic, by stamping or molding. The cross arm is elongated in a lateral direction, and includes a pair of L-shaped slots opening upwardly in an upper edge portion of the cross arm and disposed at laterally opposed ends of the cross arm. The slots are dimensioned to capture and support trellis wires. In addition, a pair of spring tabs are stamped or otherwise formed from the planar sheet of material and bent outwardly therefrom. The L-shaped slots and the spring tabs are arrayed laterally in enantiomorphic relationship. Each cross arm is dimensioned to be pushed through the slotted aperture of the vertical post described above, and the spring tab is deflected and compressed as it passes through the aperture. Thereafter, the spring tab returns (snaps back) to its extended position to prevent withdrawal of the cross arm from the slotted aperture. This arrangement permits the installation of cross arms in vertical posts without recourse to screws, bolts, or twisted wire structures, and without the use of any tool, thereby simplifying the process of trellis construction to an irreducible minimum.
In a further aspect of the invention, there is provided a trellis system that utilizes a plurality of vertical posts for trellis wire support. Each vertical post is comprised of a channel-like member formed of steel or plastic, the channel including opposed sides having vertically extending, laterally protruding convex portions. The web of the channel includes a vertically extending concave portion, and the vertically extending opening of the channel is defined by a pair of convex curved flanges extending partially into the channel cavity from the opposed sides. The convex portions and concave portion provide enhanced bending strength to the vertical post, while the channel opening prevents accumulation of water or debris within the vertical post.
Each vertical post further includes a plurality of slotted apertures in laterally paired relationship, the slotted apertures extending through the side walls of the channel. Each slotted aperture includes a pair of vertical slots formed in a channel wall in adjacent, spaced apart relationship, with a linking slot extending from the lower end of one slot to the adjacent slot. Each slot is provided with a vertical dimension sufficient to receive a cross arm of the invention in freely sliding relationship, the slot width being greater than the thickness of the cross arm but less than the width of the extended spring tab, thereby facilitating the snap-engagement of the spring members as the cross arm is passed laterally through the paired slotted apertures of the channel member.